Apparatus for stacking groups of sheets of paper or the like, hereinafter referred to as "pads" for the sake of brevity, and for transporting the stacks on to a further processing station are used in production lines for the making of books of all types and the like. Such apparatus may receive pads from a foil-applying tunnel where a transparent plastic foil, previously wrapped around each pad, is caused to shrink as a result of the application of heat which results in a close fit of each foil around the respective pad. The pads are then stacked until a predetermined number of superimposed or overlapping pads is obtained, and the stacked pads are delivered to a packing apparatus or to another processing unit.
In known apparatus of this kind, receptacles for wrapped pads are disposed above a stacking table, and each receptacle is provided with pivotable bottom panels which intercept an oncoming pad and are thereupon pivoted to open positions so as to enable an intercepted pad to descend onto the stacking table. The receptacles are adjustable to accept different formats and sizes of pads; this contributes to the initial and maintenance cost of such receptacles due to complexity of adjustable drive means for the bottom panels. An even more serious drawback of conventional apparatus of the just outlined character is that the number of receptacles determines the number of parallel tracks realizable in the entire production line; thus, the entire width of the conveyor line cannot be effectively used by an appropriate increase of tracks when the processing of relatively wide pads is followed by the processing of narrower or very narrow pads.